Circuit interrupters with pressurized interrupting assemblage and synchronized disconnecting means



3,2 14,542 ING NS Oct. 26, 1965 R. N. YECKLEY ETAL SURIZED INTERRUPT AND SYNGHRONIZED DISCONNECTING MEA CIRCUIT INTERRUPTERS WITH PRES ASSEMBLAGE Filed April 11, 1961 5 Sheets-Sheet 1 INVENTORS Russell N. Yeckley 8 Robert G. Colcloser, Jr.

ATTORNEY wnmzssss 904 v A Oct. 26, 1965 R. N. YECKLEY ETAL 3, 2

CIRCUIT INTERRUPTERS WITH PRESSURIZED INTERRUPTING ASSEMBLAGE AND SYNCHRONIZED DISCONNEGTING MEANS Filed April 11, 1961 5 Sheets-Sheet 2 Fig.2

3 3 214542 CTING MEANS Oct. 26, 1965 R. N. YECKLEY ETAL CIRCUIT INTERRUPTERS WITH PRESSURIZED INTERRUP'II ASSEMBLAGE AND SYNCHRONIZED DISCONNE Filed April 11, 1961 5 Sheets-Sheet 5 Oct. 26, 1965 R. N. YECKLEY ETAL 3,214,542

CIRCUIT INTERRUPTERS WITH PRESSURIZED INTERRUPTING ASSEMBLAGE AND SYNCHRONIZED DISCONNECTING MEANS Filed April 11, 1961 Fig. 4

5 Sheets-Sheet 4 Oct. 26, 1965 R. N. YECKLEY ETAL 3,

CIRCUIT INTERRUPTERS WITH PRESSURIZED INTERRUPTING ASSEMBLAGE AND SYNCHRONIZED DISCONNECTING MEANS Filed April 11, 1961 5 Sheets-Sheet 5 Fig. 6

United States Patent CIRCUIT INTERRUPTERS WITH PRESSURIZED INTERRUPTING ASSEMBLAGE AND SYNCHRO- NIZED DISCONNECTING MEANS Russell N. Yeckley, Murrysville, and Robert G. Colclaser, Jr., Belmont, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Apr. 11, 1961, Ser. No. 102,178 13 Claims. (Cl. 200-145) This invention relates to circuit interrupters in general, and, more particularly, to improved arc-extinguishing structures therefor.

A general object of the present invention is the provision of an improved high-power circuit-interrupting structure of simplified construction and highly efficient in operation.

A more specific object of the present invention is the provision of a high-power compressed-gas circuit interrupter employing a dead-tank construction and particularly suitable for use with a highly effective arc-extinguishing gas, such as sulfur hexafluoride (SP gas, in which the gas may be repeatedly used by employment of a suitable associated compressor equipment.

A more specific object of the present invention is the provision of an improved circuit interrupter employing a dead-tank construction, in which a disconnecting gap is provided serially into the circuit, to prevent the imposition of voltage upon insulating surfaces in the fully opencircuit position of the interrupter.

Another object of the present invention is the provision of an improved operating mechanism for a compressed-gas circuit interrupter.

A further object of the invention is the provision of novel synchronizing linkage means interposed between the disconnecting contact structure and the movable contact structure in a compressed-gas type of circuit-interrupting structure.

Another object of the invention is the provision of an improved high-voltage type of compressed-gas circuit interrupter in which shunting impedance means may be employed in shunt relationship with a plurality of seriallyrelated arc-extinguishing units to divide the voltage between the units substantially equally so that each unit performs its fair share of the interrupting burden.

Still a further object of the present invention is the provision of an improved operating mechanism for a compressed-gas circuit interrupter in which the compressedgas itself is utilized to perform the contact opening movement. As a result, there need be no reliance upon accelerating compression springs for insuring that the circuit-interrupting contact structure will move to the opencircuit position.

A more detailed object of the present invention is the provision of a novel linkage interposed between the movable disconnecting contact structure and the movable interrupting contact structure of a compressed-gas circuit interrupter to correlate their respective movement so that the interrupting function is assumed by the interrupting contact structure, whereas the isolating function is assumed by the movable disconnecting contact structure.

Still a further object of the present invention is the provision of an improved multi-break compressed-gas circuit interrupter in which novel blast-valve operating means are employed to simultaneously open and close a plurality of blast-valve structures.

In United States patent application filed January 23, 1959, Serial No. 788,668, now United States Patent 3,057,983, issued October 9, 1962, to Russell N. Yeckley, Joseph Sucha and Benjamin P. Baker, and assigned to the ice assignee of the instant application, there is disclosed and claimed a dual-pressure dead-tank type of compressed-gas circuit interrupter employing a highly efficient arc-extinguishing medium, such as sulfur-hexafiuoride (SP gas.

It is a further object of the present invention to improve upon the interrupting assemblage disclosed in the aforesaid patent application, rendering it more suitable for the withstanding of high voltage in the open-circuit position by utilizing a serially-arranged disconnecting contact structure.

Another object of the invention is to provide an improved circuit interrupter easily assembled and disassembled, in which, for inspection purposes, an interiorly-disposed arc-extinguishing assemblage may be removed from its associated casing means without necessitating a complete dismantlement of the breaker.

Further objects and advantages will readily become apparent upon reading the following specification, taken in conjunction with the drawings, in which:

FIGURE 1 is an end elevational view of a multiphase, high-power, dual-pressure dead-tank type of circuit interrupter, embodying features of the present invention;

FIG. 2 is a longitudinal sectional view taken through one of the three tank'structures of the multi-phase circuit interrupter illustrated in FIG. 1, the contact structure being illustrated in the closed-circuit position;

FIG. 3 is ia fragmentary view, drawn to an enlarged scale, and illustrating a portion of the arc-extinguishing assemblage of the interrupter of FIG. 2 with the contact structure shown in the closed-circuit position;

FIG. 4 is a view somewhat similar to that of FIG. 3, but illustrating the relative position of the several parts in the partially open-circuit position;

FIG. 5 is a sectional view taken substantially along the line VV of FIG. 3;

FIG. 6 is a fragmentary longitudinal cross-sectional view taken through the support casting disposed at the right-hand end of the arc-extinguishing assemblage;

FIG. 7 is a plan view, partially in longitudinal section, taken along the line VIIVII of the arc-extinguishing assemblage illustrated in FIG. 2; and,

FIG. 8 is a fragmentary view showing reclosure of the blast-valve structure in the fully open-circuit position of the interrupter.

Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral 1 generally designates a multi-phase, three-pole dual-pressure circuit-interrupting structure. Generally, the circuit-interrupting structure 1 includes three spaced dead or grounded tanks 2 having upstanding cylindrical support portions 3, 4, into which downwardly extend a pair of terminal bushings 5, 6. The line connections L and L are connected to the outer terminals 7, 8, as shown.

Disposed adjacent one end of the three tank structures 2 is a mechanism compartment 9 enclosing a suitable operating mechanism or operating means, not shown. The operating mechanism, not shown, may be of any suitable type, that is either pneumatic, hydraulic or solenoid actuated. The three tank structures 2 and the mechanism compartment 9 are rigidly secured to a pair of steel beams 10 so as to comprise a unitary structure. Thus, a crane may lift the entire three-phase circuit interrupter 1, and position it upon a suitable foundation 11, formed of concrete or the like.

With reference to FIG. 2, which more clearly shows the arc-extinguishing assemblage 12, it will be observed that the extinguishing assemblage 12 is clamped to the lower end 13 of the terminal bushing 6 and also to an insulating support or supporting means 14. The insulating support 14 comprises an insulating pedestal 14a secured to an upper cover plate 14b and having a lower clamping portion 14c, to which the left-hand end of the extinguishing assemblage 12 is secured, as shown.

Disconnecting means 16 are associated with the left hand end 17 of the arc-extinguishing assemblage 12. Generally, the disconnecting means 16 includes a hookshaped movable disconnecting contact 18 cooperable with relatively stationary disconnecting contact fingers 19 associated with a contact support 20. The upper end of the contact support 20 is secured to the lower end 21 of the terminal bushing 5. Preferably, the tank structure 2 includes a cylindrical portion 22 and dome-shaped end heads 23, 24. A plurality of bolts 25 and cooperating nuts may fixedly secure the end heads 23, 24 to the central portion 22 of the tank structure 2.

With reference to FIG. 3 of the drawings, it will be observed that the movable disconnecting contact 18 is rotatably mounted at a stationary pivot 26 and has a crank portion 27 pivotally connected, as at 28, to an insulating operating rod 29. As viewed in FIG. 2, the right-hand end of the insulating operating rod 29 is pivotally connected, as at 30, to a driving crank 31 keyed to a drive shaft 32. Preferably, the drive shaft 32 extends through a sealed opening out exteriorly of the tank structure 2, and has an externally-located crank-arm 33 fixedly secured therewith to effect the rotative motion thereof.

Suitable means, not disclosed, are effective to correlate the rotative movement of the three externally-located crank-arms 33 associated with the three tank structures 2 of the three-phase circuit interrupter 1. The operating mechanism, not shown, disposed internally within the mechanism compartment 9 is effective to cause, through a suitable linkage, the simultaneous movement of the several drive-cranks 33.

With reference to FIG. 3 of the drawings, it will be observed that an end support casting 34 has an upwardly extending T-shaped bracket support 35, which may be secured, as by bolts, to the lower end 140 of the insulating support 14.

The support casting 34 has an opening 36, within which is positioned a metallic bellows 37 secured, as by soldering, to an end plate or piston portion 38 and to a closure plate 39. The closure plate 39 has a gas-tight seal 40 with respect to a plate portion 41 of the end casting 34.

As shown in FIG. 3, the closure plate 39 has a spider portion 42 with a plurality of contact fingers 43 making sliding contacting engagement with a movable contact rod 44. The movable contact rod 44 is fixedly secured, as by welding, to the end plate 38, as shown. The outer extremity 45 of the movable contact rod 44 makes abutting engagement with the nose 46 of a second crank-arm 47, pivotally mounted, as at 48, within the walls of the end casting 34. As shown, a floating link 49 is pivotally connected, as at 50 and at 51, to the crank portion 27 of first rotatable crank-arm 18 and to the second crankarm 47, respectively.

The movable contact rod 44 has a movable contact structure 52 secured thereto and movable therewith. Generally, the movable contact structure 52 comprises a plurality of circumferentially-disposed fiexible contact fingers 53, which make contacting engagement with the sides 54 of an orifice-shaped relatively stationary contact 55. The relatively stationary contact 55 has an orifice opening 56 provided therein. The orifice-shaped relatively stationary contact 55 comprises a part of an exhaust-chamber assembly, generally designated by the reference numeral 57, and including an exhaust chamber 58 and a movable blast-valve assembly 59.

The movable blast-valve assembly 59 includes a blastvalve 60 having a valve stem 61 secured thereto. The valve stem 61 has a closing spring 62 encircling the same. The lower end of the closing spring 62 seats upon a spring plate63 secured to and movable with the valve stem 61. The upper end of the closing spring 62 seats against the lower surface 64 of a perforated plate 65. As shown,

the plate 65 has a plurality of gas passages 66 provided therein. To effect opening movement of the blast valve 60 upwardly away from the valve seat 67, a blast-valve lever 68 is provided, being pivotally mounted on a stationary pivot 69. The blast-valve lever 68 has an abutment pin 70 extending laterally therefrom, which, through a thrust roller 15, makes abutting engagement with the valve stem 61, as shown.

To elfect opening movement of the blast-valve lever 68 about its stationary pivot 69, an actuating portion 71 is provided, which makes abutting engagement with the extremity 72 of the movable contact rod 44 of the adjacently-disposed interrupting unit 73. Additional contact fingers 43 carry the current from the movable contact rod 44 of said adjacent unit 73 to the exhaust chamber assembly 57 Surrounding the two gas-blast interrupting units 73 of the arc-extinguishing assemblage 12 is an insulating tubular casing 74 having a plurality of threaded holes 75 provided at the upper side thereof, as shown more clearly in FIG. 2 of the drawings.

With reference to FIGS. 5 and 7 of the drawings, it will be apparent that the movable contact assemblage 76 of the arc-extinguishing assemblage 12 comprises generally a pair of insulating operating rods 77 bridged by cross-supports 78. The movable contact structures 52 are attached adjacent the middle portions of the crosssupports 78 so that the entire movable contact assemblage 76 forms generally a ladder-shaped assemblage and is movable as a unit.

The surrounding tubular casing 74 makes a pressuretight engagement, as at 79 in FIG. 3, with the plate portion 41 of the end casting 34. As a result, the region 80 interiorly of the tubular casing 74 constitutes a highpressure reservoir chamber, which is fed with high-pres sure gas, say sulfur-hexafiuoride (SP gas at a pressure of 220 p.s.i. Preferably, a high-pressure feed tube 81 (FIG. 2) is provided to maintain the pressure within the region 80 interiorly of the outer casing 74 at the desired high-pressure level.

To effect a closing operation of the interrupter, the several crank-arms 33 are simultaneously moved in a clockwise direction about their pivot axes 32. This will exert tension upon the insulating operating rods 29 and cause simultaneous closing movement of the movable dis- Connecting contacts 18 together with clockwise rotation of the several crank-arms 47 associated with the tank structures 2 to thereby effect rightward closing movement of the several movable contact assemblages '76. Closing of the movable contact structures 52 into engagement with the relatively stationary orifice-shaped contacts 56 will result in effecting closing of the electrical circuit through the interrupter 1. In the fully closed-circuit positio n of the interrupter 1, the electrical circuit therethrough includes line connection L terminal stud '7, contact support 20, relatively stationary disconnecting contact fingers 19, movable disconnecting contact 18, pivot axis 26 (FIG. 3), end casting 34, conducting plate 39, spider portion 42, contact fingers 43, movable contact rod 44, relatively movable contact structure 52, relatively stationary contact structure 55, and onward in similar manner through the adjacent interrupting unit 73 to the right-hand end casting 82 (FIG. 6) to right-hand terminal bushing 6. The circuit then extends to the outer terminal 8 and hence to line connection L Preferably the tank structure 2 serves as an exhaust chamber to collect the gas which is exhausted during the circuit-interrupter opening operation, and suitable compressor means, not shown, are provided within the mech anism compartment 9 to effect recompression of the exhausted sulfur-hexafiuoride (SP .gas to the desired highpressure level. A high-pressure storage tank, not shown, is disposed within the mechanism compartment 9 and stores the gas under high pressure. The gas is then fed through a horizontally-extending feed pipe 84 and to the branch connections 81 to supply the several reservoir chambers 80 of the extinguishing assemblages 12.

.The opening operation of the circuit interrupter 1 will now be described. When it is desired to effect the opening of the circuit passing through the circuit interrupter 1-, a mechanism or operating means, not shown disposed within the mechanism compartment 9, is unlatched. This will permit the pressure P within the region 80, which is at the high-pressure level, say 220 p.s.i., to force the pressure plate or piston portion 38 toward the left and effect leftward opening movement of the movable contact assemblage 76. The blade portioh -85 of the movable disconnecting contact 18 has a sliding connection with the relatively stationary disconnecting contact fingers 19, and the floating link 49 is such that the movable cohtact assemblage 76 will effect are extinction prior to withdrawal of the movable disconnecting contact 85 from the disconnecting fingers 19. As a result, interruption of the circuit will take place entirely within the arc-extihguishing assemblage 12 and not at the gap between the disconnecting contacts 19, 85.

With reference to .FIG. 3 of the drawings, it will be observed that leftward opening movement of the movable contact assemblage 76 will cause the movable contact rods 44 to effect clockwise opening movement of the blastvalve levers 68 to effect upward opening movement of the several blast valves 60. This will permit the high-pressure gas within the region 86 to exhaust below the lower lip '87 of, the blast-valve 60 and out through the interior thereof in the manner illustrated by the arrows 88 in FIG. 4. Hence, FIG. 4 more clearly illustrates the gas passage during the opening operation.

, Preferably suitable screening 89 is provided to cool the gases as they exhaust through the orifice opening 56 extinguishing the arc 90 drawn between the movable contact 52 and the relatively stationary contact 55.

- With reference to FIG. 8, it will be noted that following a predetermined opening travel of the movable cohtact rods 44, the actuating portion 72, or extremity of rod 44, will move past the valve lever 71, thereby permitting the blastvalve 60 to reclose by spring pressure shutting off the exhausting flow of high-pressure gas through the opening'93. As mentioned previously, following interruption of the circuit at the arc-extinguishing assemblage 12, the movable disconnecting contact 18 will separate from the relatively stationary disconnecting contact fingers .19 inserting an isolating gap into the circuit, as shown by the dotted lines 1811 of FIG. 2. This has two important advantages. The first advantage is that insulation is not subjected to voltage stress in the fully open-circuit position of the interrupter 1. Secondly, voltage-dividing means 95, comprising resistor tubes 96, may be employed to divide the voltage substantially equally between the two gas-blast interruptihg units 73. For high-voltage application, this substantially equal division of voltage between the units 73 is important, so that each interrupting unit 73 in a multi-break series of units 73 interrupts its fair share of the current and voltage.

1 From the foregoing description, it will be apparent that there is provided an improved compressed-gas type of circuit interrupter 1 employing a unique advantage not found on present-type compressed-gas breaker designs utilizing a dead-tank construction. This advantage is the employme'nt of a disconnecting break. All of the inherent advantages of the dead-tank design, including inexpensive current transformers 97 are retained. The disconnecting break incorporates two desirable features into the construction. First, wheln the breaker 1 is in the open-circuit position, a minimum amount of organic insulation is stressed. In some designs, when the breaker is open, during out-of-phase conditions, organic insulation is stressed to substalntially twice normal voltage between the bushings. This is eliminated in the'present construction. Secondly, the use of a disconnecting gap permits the use of high-ohmic grading resistors to distribute the recovery 6 voltage equally between the breaks. This is important in the case of multiple breaks, since if more than three breaks are used, it is difidcult to obtain equal distributioln using capacitor dividers only.

With the construction illustrated in FIG. 2, it will be noted that a two-unit breaker assemblage 12 is illustrated, with the interrupting assemblage 12 suspended from one bushing 6 and the porcelain support 14 being used at the other end. The disco nnecting gap is between the insulating support 14 and the remaining terminal bushing 5.

The tubular insulating casing 74 provides the necessary insulation, and also serves to shield the moving parts of the interrupter 1. The seals for the gas-tight construction are illustrated.

An important advantage of the present construction is that by unscrewing the sub-valve assemblies 98 at the break line 99 and removing them from the casing 74 out of the openings 75, the entire removable contact structure 92, including the exhaust chamber assemblies 57, the tie-rods 100, together with end plates 39, may be removed completely out of the right-hand end of the arcextinguishing casing 74. FIG. 6 more clearly shows this construction wherein during such a removal operation, the end castings 34, 82 remain fixedly in position.

Thus, as shown in FIG. 6, the end casting 82 has a hollow portion 104, through which the end plate 105 may be removed during the previously-described disassembly operation. Jack screws 106, secured to removable brackets 107, the latter being bolted by bolts 108, may be employed to clamp the end plates 39, 105 into an operative position, whereby gasket means 40, 79, and may be employed to effect a pressurized condition within the casing 74. Preferably guide means may be employed to guide the longitudinal reciprocal motion of the conducting rod 116 associated with the movable contact assembly 7 6. A flexible connector 117 electrically interconnects the contact foot 118 with the relatively stationary guide fingers 119 in an obvious manner.

7 From the foregoing description it will be apparent that there is provided a compressed-gas interrupting assemblage 12 of highly effective operation, and readily capable of assembly, or disassembly by mere removal of the flexible connector 117 and the jack screws 106 with supporting brackets 107. As a result, the end castings 34, 82 may remain in a fixed position during the disassembly of the operating rods 100 and the movable contact assemblage 76 together with the end plates 39, 105 during such a sub-disassembly operation.

. It is to be noted that by utilizing the pressure P within pressurized casing 74, assurance is had that positive opening operation of the movable contact assemblage 76 will be obtained. A complicated opening linkage is, as a result of the improved construction, unnecessary; and trouble-free operation is obtained from the simplicity achieved.

6 It will also be evident to those skilled in the art that certain features of the present invention are applicable to other types of circuit interrupters than the compressedair type. For instance in certain oil circuit interrupters, advantage may be obtained by the particular support of the assemblage 12 and the associated disconnecting contact structure 16. In such an instance, a positive drive for the movable contact assemblage 76 could be used, instead of pressure, and an explosion-pot liquid-blast action through the orifice openings 56 could be obtained in such an oil circuit interrupter modification.

Although there has been illustrated and described a specific structure, it is to be clearly understood that the same was merely for the purpose of illustration, and that changes and modifications may readily be made therein by those skilled in the art, without departing from the spirit and scope of the invention.

We claim as our invention:

1. A circuit interrupter including means defining a tank, a pair of terminal bushings extending interiorly of said 7 tank, a supporting means mounted within said tank, a pressurized interrupting assemblage including at least one arc-extinguishing unit disposed within said tank, said supporting means and one of said terminal bushings at least partially supporting said interrupting assemblage, contact means associated with said one unit, means including the pressure stored by the pressurized assemblage to effect opening of said contact means, operating means, said operating means mechanically maintaining said contact means closed in the closed-circuit position of the interrupter against the opening biasing force exerted by said stored high pressure, means for releasing said operating means during the opening operation, whereby the stored high pressure will effect opening of said contact means, and disconnecting means electrically connected in series with said contact means associated with the other of the two terminal bushings and with the supportingmeans end of the assemblage.

2. The combination in a dead-tank type of circuit interrupter of an elongated grounded dead-tank, a pair of terminal bushings extending interiorly of said tank, supporting means mounted within said tank, a pressurized interrupting assemblage including at least one arc-extinguishing unit disposed within said tank, said supporting means and one of said terminal bushings at least partially supporting said interrupting assemblage, contact means associated with said one unit, means including the pressure stored by the pressurized assemblage to effect opening of said contact means, operating means, said operating means mechanically maintaining said contact means closed in the closed-circuit position of the interrupter against the opening biasing force exerted by said stored high pressure, means for releasing said operating means during the opening operation, whereby the stored high pressure will effect opening of said contact means, a relatively stationary disconnecting contact supported by the interior end of the other terminal bushing, and a cooperable movable disconnecting contact electrically connected in series with said contact means and supported by one end of the interrupting assemblage, whereby separation of the movable disconnecting contact from said relatively stationary disconnecting contact inserts an isolating gap into the circuit following the arc extinction process.

3. A compressed-gas circuit interrupter including a grounded exhaust tank, a pair of terminal bushings extending interiorly of said tank, a support bushing mounted within said tank, an interrupting assemblage including at least one arc-extinguishing unit disposed within said tank, said support bushing and one of said terminal bushings at least partially supporting said interrupting assemblage, means pressurizing said interrupting assemblage at a higher pressure than is present within said grounded exhaust tank, separable contact means associated with each of said one or more arc-extinguishing units, disconnecting means electrically connected in series with said contact means associated with the other of the two terminal bushings and with the support-bushing end of the assem blage, means utilizing the pressure within the pressurized interrupting assemblage to etfect contact separation within the one or more of the arc-extinguishing units, and operating means, said operating means mechanically maintaining said contact means closed in the closed-circuit position of the interrupter against the opening biasing force exerted by said stored high pressure, means for releasing said operating means during the opening opera tion, whereby the stored high pressure will elfect opening of said contact means.

4. A gas-blast interrupting assemblage for a compressed-gas circuit interrupter including a pressurized casing, a plurality of serially-related gas-blast interrupting units disposed along said casing, a plurality of exhaust valve structures in the wall of the pressurized casing, a generally ladder-shaped movable contact assemblage comprising a pair of insulating operating rods and cross-bars, a movable contact having an extension secured adjacent the center of at least one cross-bar, a plurality of relatively stationary contacts, and said contact extension actuating one Of the exhaust valve structures for the adjacent gas-blast interrupting unit.

5. The combination in a dead-tank type of circuit interrupter of an elongated grounded dead-tank, a pair of terminal bushings extending interiorly of said tank, a support bushing mounted within said tank, an interrupting assemblage including at least a pair of gas-blast interrupting units disposed within said tank, said interrupting assemblage also including a generally ladder-shaped movable contact assemblage comprising a pair of insulating operating rods and cross-bars, a movable contact having an extension secured adjacent the center of at least one cross-bar, a plurality of relatively stationary contacts, and said contact extension actuating one of the exhaust valve structures for the adjacent gas-blast interrupting unit, said support bushing and one of said terminal bushings at least partially supporting said interrupting assemblage, a relatively stationary disconnecting contact supported by the interior end of the other terminal bushing, and a cooperable movable disconnecting contact supported by one end of the interrupting assemblage, whereby separation of the movable disconnecting contact from said relatively stationary disconnecting contact inserts an isolating gap into the circuit following the arc extinction process.

6. A circuit interrupter of the gas-blast type including means defining a grounded tank, a pair of terminal bushings extending interiorly of said tank, a support bushing mounted within said tank, an interrupting assemblage including a pressurized casing having a plurality of arcextinguishing gas-blast interrupting units disposed within said tank, said support bushing and one of said terminal bushings at least partially supporting said interrupting assemblage, disconnecting means associated with the other of the two terminal bushings and with the support-bushing end of the assemblage, said interrupting assemblage including a generally ladder-shaped movable assemblage comprising a pair of insulating operating rods and crossbars, a movable contact having an extension secured adjacent the center of at least one cross-bar, a plurality of relatively stationary contacts, and said contact extension actuating one of the exhaust-valve structures for the adjacent gas-blast interrupting unit.

7. The combination in an elongated grounded deadtank type of compressed-gas circuit interrupter of a pair of terminal bushings extending into the grounded tank adjacent opposite ends thereof, a support bushing mounted within said tank, a pressurized interrupting assemblage in-v cluding at least a pair of gas-blast interrupting units disposed within said grounded tank, said support bushing and one of said terminal bushings at least partially supporting said interrupting assemblage, a rotatable disconnecting means associated with the other of the two terminal bush ings and with the support-bushing end of the assemblage, said pressurized interrupting assemblage including a generally ladder-shaped movable contact assemblage comprising a pair of insulating operating rods and interconnecting cross-bars, a movable contact having an extension secured adjacent the end of at least one cross-bar, a plurality of relatively stationary contacts, and said contact extension actuating one of the exhaust-valve structures for the adjacent gas-blast interrupting unit.

8. A compressed-gas circuit interrupter including a tubular pressurized casing, a pair of metallic end castings disposed at opposite ends of said pressurized casing, one of said metallic end castings having a hollow tubular portion, through which said pressurized casing may be removed, and jacking means associated with said one metallic end casting for clamping said tubular pressurized casing into an operative position.

9. The combination in a compressed-gas circuit interrupter of a grounded tank, a pair of terminal bushings extending into said grounded tank adjacent opposite ends thereof, a support bushing extending within said grounded tank, a pressurized arc-extinguishing assemblage including a pressurized casing and a pair of oppositely disposed metallic end castings, one of said metallic end castings having a hollow portion, through which said pressurized casing may be removed, and rotatable disconnecting means associated with the other end casing.

10. A compressed-gas circuit interrupter including a pressurized arc-extinguishing assembly having a movable contact structure, disconnecting means serially related to said pressurized arc-extinguishing assemblage and including a rotatable disconnecting first crank arm carrying a movable disconnecting contact, a relatively stationary dis connecting contact having a wiping contact with said movable disconnecting contact, means pivotally mounting said rotatable disconnecting firstcrank arm on a fixed pivot, a second rotatable crank arm, linkage means mechanically interconnecting the first and second crank arms, an operating rod pivotally connected to said first crank arm, said movable contact structure having a piston portion acted upon by the pressure within the pressurized arc-extinguishing assemblage, whereby release of the operating rod permits opening motion of the movable contact structure to eifect thereby rotative travel of said first and second crank arms to effect circuit interruption at the pressurized arc-extinguishing assemblage prior to disconnection at said movable and relatively stationary disconnecting contacts.

11. A compressed-gas circuit interrupter including a grounded tank, a pair of terminal bushings extending into said grounded tank, a support bushing disposed within said grounded tank, a pressurized arc-extinguishing assemblage at least partially supported at the interior end of one of said terminal bushings and at the interior end of said support bushing, disconnecting means disposed between the interior end of the other terminal bushing and said arc-extinguishing assemblage, said disconnecting means including a rotatable disconnecting first crank arm carrying a movable disconnecting contact, said disconnecting means also including a relatively stationary disconnecting contact supported by the interior end of said other bushing, means pivotally mounting said rotatable disconnecting first crank arm on a fixed pivot supported upon said arc-extinguishing assemblage, a second rotatable crank arm, linkage means mechanically intercon necting the first and second crank arms, an insulating operating rod pivotally connected to said first crank arm and extending adjacent a wall of said grounded tank, said arc-extinguishing assemblage including movable contact structure having a piston portion acted upon by the pressure within the pressurized arc-extinguishing assemblage, whereby release of said operating rod permits opening motion of the movable contact structure by the pressure of said pressurized arc-extinguishing assemblage acting upon said piston portion and consequent rotative travel of said first and second crank arms to effect circuit interruption within the pressurized arc-extinguishing assemblage prior to disconnection at said movable and relatively stationary disconnecting contacts.

12. The combination in a compressed-gas circuit interrupter of a grounded exhaust tank, a pair of terminal bushings extending into said grounded exhaust tank, a support bushing extending within said grounded exhaust tank, a pressurized arc-extinguishing assemblage supported between said support bushing and one of said terminal bushings, disconnecting means serially related to said pressurized arc-extinguishing assemblage and including a relatively stationary disconnecting contact supported by the interior end of the other terminal bushing and a rotatable disconnecting first crank arm carrying a movable disconnecting contact, means pivotally mounting said rotatable disconnecting first crank arm on a fixed pivot supported by said arc-extinguishing assemblage, a second rotatable crank arm, linkage means mechanically interconnecting the first and second crank arms, an insulating operating rod pivotally connected to said first crank arm and extending adjacent a wall of said grounded exhaust tank, said arc-extinguishing assemblage including movable contact structure having a piston portion acted upon by the pressure within the pressurized arc-extinguishing assemblage, said relatively stationary disconnecting contact having a wiping contact with said movable disconnecting contact, whereby release of said movable operating rod permits opening motion of said movable contact structure and consequent rotative travel of said first and second crank arms to eifect thereby circuit interruption within the pressurized arc-extinguishing assemblage prior to disconnection at said movable and relatively stationary disconnecting contacts.

13. The combination according to claim 1, wherein the tank constitutes an exhaust volume, and said disconnecting means is synchronized to open after the separation of the contact means for inserting an isolating gap into the circuit.

References Cited by the Examiner UNITED STATES PATENTS 2,459,600 1/49 Strom 200-148 2,724,751 11/55 Forwald 200---148 2,981,815 4/61 Leeds et a1 200148 FOREIGN PATENTS 1,222,392 1 France.

582,599 11/46 Great Britain. 605,163 7/48 Great Britain.

KATHLEEN'H. CLAFFY, Primary Examiner.

MAX L. LEVY, BERNARD A. GILHEANY,

Examiners. 

1. A CIRCUIT INTERRUPTER INCLUDING MEANS DEFINING A TANK, A PAIR OF TERMINAL BUSHINGS EXTENDING INTERIORLY OF SAID TANK, A SUPPORTING MEANS MOUNTED WITHIN SAID TANK, A PRESSURIZED INTERRUPTING ASSEMBLAGE INCLUDING AT LEAST ONE ARC-EXTINGUISHING UNIT DISPOSED WITHIN SAID TANK, SAID SUPPORTING MEANS AND ONE OF SAID TERMINAL BUSHINGS AT LEAST PARTIALLY SUPPORTING SAID INTERRUPTING ASSEMBLAGE, CONTACT MEANS ASSOCIATED WITH SAID ONE UNIT, MEANS INCLUDINF THE PRESSURE STORED BY THE PRESSURIZED ASSEMBLAGE TO EFFECT OPENING OF SAID CONTACT MEANS, OPERATING MEANS, SAID OPERATING MEANS MECHANICALLY MAINTAINING SAID CONTACT MEANS CLOSED IN THE CLOSED-CURCUIT POSITION OF THE INTERRUPTER AGAINST THE OPENING BIASING FORCE EXERTED BY SAID STORED HIGH PRESSURE, MEANS FOR RELEASING SAID OPERATING MEANS DURING THE OPENING OPERATION, WHEREBY THE STORED HIGH PRESSURE WILL EFFECT OPENING OF SAID CONTACT MEANS, AND DISCONNECTING MEANS ELECTRICALLY CONNECTED IN SERIES WITH SAID CONTACT MEANS ASSOCIATED WITH THE OTHER OF THE TWO TERMINAL BUSHINGS AND WITH THE SUPPORTINGMEANS END OF THE ASSEMBLAGE. 